py3: use print as a function in tests/test-revert.t

This makes the test work on Python 3.

Differential Revision: https://phab.mercurial-scm.org/D4687

contrib/python3-whitelist

@@ -471,6 +471,7 b' test-resolve.t'
 test-revert-flags.t
 test-revert-interactive.t
 test-revert-unknown.t
+test-revert.t
 test-revisions.t
 test-revlog-ancestry.py
 test-revlog-group-emptyiter.t

tests/test-revert.t

@@ -532,6 +532,7 b' Script to make a simple text version of '
 
   $ cat << EOF >> dircontent.py
   > # generate a simple text view of the directory for easy comparison
+  > from __future__ import print_function
   > import os
   > files = os.listdir('.')
   > files.sort()
@@ -539,7 +540,7 b' Script to make a simple text version of '
   >     if os.path.isdir(filename):
   >         continue
   >     content = open(filename).read()
-  >     print '%-6s %s' % (content.strip(), filename)
+  >     print('%-6s %s' % (content.strip(), filename))
   > EOF
 
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